package com.zjz.demo.rw;

import java.util.HashMap;
import java.util.Locale;
import java.util.Map;
import java.util.concurrent.locks.Lock;
import java.util.concurrent.locks.ReadWriteLock;
import java.util.concurrent.locks.ReentrantLock;
import java.util.concurrent.locks.ReentrantReadWriteLock;

/**
 * Created with IntelliJ IDEA.
 *
 * @Author: zjz
 * @Date: 2021/10/08/21:02
 * @Description:
 * @Target: ReadWriteLock
 */
public class ReadWriteLockDemo {

    /*
    * 自定义缓存  set get put
    * */

    public static void main(String[] args) {
        MyCache myCache = new MyCache();


        // 写入操作
        for (int i = 0; i < 7; i++) {
            final int temp = i;
            new Thread(()->{
                myCache.put(temp+"",temp+"");
            },String.valueOf(i)).start();
        }

        // 读取操作
        for (int i = 0; i < 7; i++) {
            final int temp = i;
            new Thread(()->{
                myCache.get(temp+"");
            },String.valueOf(i)).start();
        }




    }



}


class MyCacheLock{
    private volatile Map<String,Object> map = new HashMap<>();
//    private Lock lock = new ReentrantLock();
    // 读写锁:更加细粒度的控制
    private ReadWriteLock readWriteLock= new ReentrantReadWriteLock();



    // 存---写 只希望同时有一个线程写
    public void put(String key,Object value){


        try{
            readWriteLock.writeLock().lock();
            System.out.println(Thread.currentThread().getName()+"写入"+key);
            map.put(key, value);
            System.out.println(Thread.currentThread().getName()+"写入OK");
        }catch (Exception e){
            e.printStackTrace();
        }finally {
            readWriteLock.writeLock().unlock();
        }

    }

    // 取---读  所有人都可以读
    public void get(String key){

        try {
            readWriteLock.readLock().lock();
            System.out.println(Thread.currentThread().getName()+"读取"+key);
            Object o = map.get(key);
            System.out.println(Thread.currentThread().getName()+"读取OK");

        } catch (Exception e) {
            e.printStackTrace();
        } finally {
            readWriteLock.readLock().unlock();
        }


    }

}













class MyCache{
    private volatile Map<String,Object> map = new HashMap<>();

    // 存---写
    public void put(String key,Object value){
        System.out.println(Thread.currentThread().getName()+"写入"+key);
        map.put(key, value);
        System.out.println(Thread.currentThread().getName()+"写入OK");
    }

    // 取---读
    public void get(String key){
        System.out.println(Thread.currentThread().getName()+"读取"+key);
        Object o = map.get(key);
        System.out.println(Thread.currentThread().getName()+"读取OK");

    }

}
